Various types of subsurface well safety devices are utilized in a well tubing to shut off the production of well fluids from oil or gas wells in which the opening and closing of the valve is controlled by movement of a flow tube. However, the well safety valve may fail from various causes. If the safety valve is retrievable, it must be removed and repaired, but if it forms a portion of the well tubing the tubing string must be pulled to perform any safety valve repairs.
Such operations are costly and time-consuming. It is sometimes desirable to delay the repair of the safety valve but still work on or produce from the well. To do this, the safety valve is locked out, which means it is mechanically moved to the fully opened position for the purpose of producing from the well or performing other work in the tubing below the safety valve. While a lock-out of the safety valve will not eliminate the need for pulling the safety valve or tubing for repair, the lock-out will allow the well to stay on production or perform other work functions in the tubing until the safety valve can be conveniently scheduled. Various types of mechanical lock-outs have been proposed in U.S. Pat. Nos. 3,696,868; 3,786,865; and 3,786,866. However, the use of such mechanical lock-outs increases the cost of the safety valve. In addition, the lock-outs are not used approximately 99% of the time. Furthermore, the mechanical lock-outs, since they are not operated for extended periods of time, for instance years, and are not operated normally or periodically; may themselves fail for various reasons such as sand buildup.
The present invention is directed to a method and apparatus for locking out a subsurface safety valve in the open position in which the usual mechanical lock-out may be omitted. This is achieved by making one or more outward indentations in the flow tube after it is moved towards the open position and opens the valve closure member, whereby the indentations will engage a downwardly directed shoulder on the valve housing thus preventing the flow tube and the valve from moving to the closed position.